An embodiment relates to in-vehicle messaging.
Controller-area network (CAN) is a vehicle bus standard that allows electronic control units (ECUs) and other devices to communicate with one another without a central or host computer. Vehicle systems and subsystems, as well as other types of non-automotive systems including trains, planes, and ships, have numerous ECUs that receive data from sensing devices and communicate to other ECUs of the vehicle.
The CAN system is an asynchronous broadcast serial bus which allows messages to be communicated serially. Therefore, messages between ECUs when transmitted are not necessarily transmitted immediately over the CAN bus when a message is generated. If the CAN bus is free, the message is instantly transmitted. If more than one message is transmitted, the more dominant message is transmitted. This is known as an arbitration process. A CAN message with a highest priority typically will dominate the arbitration and a message transmitting at the lower priority will sense this and wait.
Despite messages being transmitted within a vehicle, there still needs to be secure messaging to make sure that systems are not compromised and malicious messages are not transmitted within the system which could cause safety concerns. For example, with the introduction of automated cruise control and other automated driving operations, security must still be maintained with respect to communicating ECUs, otherwise a malicious node could compromise the system and cause unintended vehicle operations.